#!/usr/bin/env python
#coding:utf8

def read():
    return map(int, raw_input().split(':'))


def work((HH, MM)):
    mins = (HH * 60 + MM + 5) % (24 * 60)
    print "%02d:%02d" % (mins / 60, mins % 60)


if __name__ == "__main__":
    work(read())